Java Code Examples for org.apache.flink.streaming.api.functions.sink.DiscardingSink

/**
 * These check whether timestamps are properly assigned at the sources and handled in
 * network transmission and between chained operators when timestamps are enabled.
 */
@Test
public void testTimestampHandling() throws Exception {
	final int numElements = 10;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime);
	env.setParallelism(PARALLELISM);
	env.getConfig().disableSysoutLogging();

	DataStream<Integer> source1 = env.addSource(new MyTimestampSource(0L, numElements));
	DataStream<Integer> source2 = env.addSource(new MyTimestampSource(0L, numElements));

	source1
			.map(new IdentityMap())
			.connect(source2).map(new IdentityCoMap())
			.transform("Custom Operator", BasicTypeInfo.INT_TYPE_INFO, new TimestampCheckingOperator())
			.addSink(new DiscardingSink<Integer>());

	env.execute();
}
 

/**
 * These check whether timestamps are properly ignored when they are disabled.
 */
@Test
public void testDisabledTimestamps() throws Exception {
	final int numElements = 10;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	env.setStreamTimeCharacteristic(TimeCharacteristic.ProcessingTime);
	env.setParallelism(PARALLELISM);
	env.getConfig().disableSysoutLogging();

	DataStream<Integer> source1 = env.addSource(new MyNonWatermarkingSource(numElements));
	DataStream<Integer> source2 = env.addSource(new MyNonWatermarkingSource(numElements));

	source1
			.map(new IdentityMap())
			.connect(source2).map(new IdentityCoMap())
			.transform("Custom Operator", BasicTypeInfo.INT_TYPE_INFO, new DisabledTimestampCheckingOperator())
			.addSink(new DiscardingSink<Integer>());

	env.execute();
}
 

public static void main(String[] args) throws Exception {
	final ParameterTool pt = ParameterTool.fromArgs(args);
	final String checkpointDir = pt.getRequired("checkpoint.dir");

	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setStateBackend(new FsStateBackend(checkpointDir));
	env.setRestartStrategy(RestartStrategies.noRestart());
	env.enableCheckpointing(1000L);
	env.getConfig().disableGenericTypes();

	env.addSource(new MySource()).uid("my-source")
			.keyBy(anInt -> 0)
			.map(new MyStatefulFunction()).uid("my-map")
			.addSink(new DiscardingSink<>()).uid("my-sink");
	env.execute();
}
 

public void doTestPropagationFromCheckpointConfig(boolean failTaskOnCheckpointErrors) {
	StreamExecutionEnvironment streamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment();
	streamExecutionEnvironment.setParallelism(1);
	streamExecutionEnvironment.getCheckpointConfig().setCheckpointInterval(1000);
	streamExecutionEnvironment.getCheckpointConfig().setFailOnCheckpointingErrors(failTaskOnCheckpointErrors);
	streamExecutionEnvironment.addSource(new SourceFunction<Integer>() {

		@Override
		public void run(SourceContext<Integer> ctx) {
		}

		@Override
		public void cancel() {
		}

	}).addSink(new DiscardingSink<>());
}
 

/**
 * Test whether an {@link OutputTypeConfigurable} implementation gets called with the correct
 * output type. In this test case the output type must be BasicTypeInfo.INT_TYPE_INFO.
 */
@Test
public void testOutputTypeConfigurationWithOneInputTransformation() throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	DataStream<Integer> source = env.fromElements(1, 10);

	OutputTypeConfigurableOperationWithOneInput outputTypeConfigurableOperation = new OutputTypeConfigurableOperationWithOneInput();

	DataStream<Integer> result = source.transform(
		"Single input and output type configurable operation",
		BasicTypeInfo.INT_TYPE_INFO,
		outputTypeConfigurableOperation);

	result.addSink(new DiscardingSink<>());

	env.getStreamGraph();

	assertEquals(BasicTypeInfo.INT_TYPE_INFO, outputTypeConfigurableOperation.getTypeInformation());
}
 

/**
 * Tests that the max parallelism is properly set for connected
 * streams.
 */
@Test
public void testMaxParallelismWithConnectedKeyedStream() {
	int maxParallelism = 42;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	DataStream<Integer> input1 = env.fromElements(1, 2, 3, 4).setMaxParallelism(128);
	DataStream<Integer> input2 = env.fromElements(1, 2, 3, 4).setMaxParallelism(129);

	env.getConfig().setMaxParallelism(maxParallelism);

	DataStream<Integer> keyedResult = input1
			.connect(input2)
			.keyBy(value -> value, value -> value)
			.map(new NoOpIntCoMap());

	keyedResult.addSink(new DiscardingSink<>());

	StreamGraph graph = env.getStreamGraph();

	StreamNode keyedResultNode = graph.getStreamNode(keyedResult.getId());

	StreamPartitioner<?> streamPartitioner1 = keyedResultNode.getInEdges().get(0).getPartitioner();
	StreamPartitioner<?> streamPartitioner2 = keyedResultNode.getInEdges().get(1).getPartitioner();
}
 

public void doTestPropagationFromCheckpointConfig(boolean failTaskOnCheckpointErrors) throws Exception {
	StreamExecutionEnvironment streamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment();
	streamExecutionEnvironment.setParallelism(1);
	streamExecutionEnvironment.getCheckpointConfig().setCheckpointInterval(1000);
	streamExecutionEnvironment.getCheckpointConfig().setFailOnCheckpointingErrors(failTaskOnCheckpointErrors);
	streamExecutionEnvironment.addSource(new SourceFunction<Integer>() {

		@Override
		public void run(SourceContext<Integer> ctx) throws Exception {
		}

		@Override
		public void cancel() {
		}

	}).addSink(new DiscardingSink<>());

	StreamGraph streamGraph = streamExecutionEnvironment.getStreamGraph();
	JobGraph jobGraph = StreamingJobGraphGenerator.createJobGraph(streamGraph);
	SerializedValue<ExecutionConfig> serializedExecutionConfig = jobGraph.getSerializedExecutionConfig();
	ExecutionConfig executionConfig =
		serializedExecutionConfig.deserializeValue(Thread.currentThread().getContextClassLoader());

	Assert.assertEquals(failTaskOnCheckpointErrors, executionConfig.isFailTaskOnCheckpointError());
}
 

/**
 * Tests that there are no collisions with two identical intermediate nodes connected to the
 * same predecessor.
 *
 * <pre>
 *             /-> [ (map) ] -> [ (sink) ]
 * [ (src) ] -+
 *             \-> [ (map) ] -> [ (sink) ]
 * </pre>
 */
@Test
public void testNodeHashIdenticalNodes() throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.createLocalEnvironment();
	env.setParallelism(4);
	env.disableOperatorChaining();

	DataStream<String> src = env.addSource(new NoOpSourceFunction());

	src.map(new NoOpMapFunction()).addSink(new DiscardingSink<>());

	src.map(new NoOpMapFunction()).addSink(new DiscardingSink<>());

	JobGraph jobGraph = env.getStreamGraph().getJobGraph();
	Set<JobVertexID> vertexIds = new HashSet<>();
	for (JobVertex vertex : jobGraph.getVertices()) {
		assertTrue(vertexIds.add(vertex.getID()));
	}
}
 

/**
 * Creates a streaming JobGraph from the StreamEnvironment.
 */
private JobGraph createJobGraph(
	int parallelism,
	int numberOfRetries,
	long restartDelay) {

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(parallelism);
	env.disableOperatorChaining();
	env.getConfig().setRestartStrategy(RestartStrategies.fixedDelayRestart(numberOfRetries, restartDelay));
	env.getConfig().disableSysoutLogging();

	DataStream<Integer> stream = env
		.addSource(new InfiniteTestSource())
		.shuffle()
		.map(new StatefulCounter());

	stream.addSink(new DiscardingSink<>());

	return env.getStreamGraph().getJobGraph();
}
 

@Test
public void testEndInput() throws Exception {
	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(1);
	final File sourceFile = TEMPORARY_FOLDER.newFile();
	final int elementCount = 10000;
	try (PrintWriter printWriter = new PrintWriter(sourceFile)) {
		for (int i = 0; i < elementCount; i++) {
			printWriter.println(i);
		}
	}

	DataStreamSource<String> source = env.readTextFile(sourceFile.getAbsolutePath());

	// check the endInput is invoked at the right time
	TestBoundedOneInputStreamOperator checkingOperator = new TestBoundedOneInputStreamOperator(elementCount);
	DataStream<String> endInputChecking = source.transform("EndInputChecking", STRING_TYPE_INFO, checkingOperator);

	endInputChecking.addSink(new DiscardingSink<>());

	env.execute("ContinuousFileReaderOperatorITCase.testEndInput");
}
 

/**
 * These check whether timestamps are properly assigned at the sources and handled in
 * network transmission and between chained operators when timestamps are enabled.
 */
@Test
public void testTimestampHandling() throws Exception {
	final int numElements = 10;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime);
	env.setParallelism(PARALLELISM);
	env.getConfig().disableSysoutLogging();

	DataStream<Integer> source1 = env.addSource(new MyTimestampSource(0L, numElements));
	DataStream<Integer> source2 = env.addSource(new MyTimestampSource(0L, numElements));

	source1
			.map(new IdentityMap())
			.connect(source2).map(new IdentityCoMap())
			.transform("Custom Operator", BasicTypeInfo.INT_TYPE_INFO, new TimestampCheckingOperator())
			.addSink(new DiscardingSink<Integer>());

	env.execute();
}
 

/**
 * These check whether timestamps are properly ignored when they are disabled.
 */
@Test
public void testDisabledTimestamps() throws Exception {
	final int numElements = 10;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	env.setStreamTimeCharacteristic(TimeCharacteristic.ProcessingTime);
	env.setParallelism(PARALLELISM);
	env.getConfig().disableSysoutLogging();

	DataStream<Integer> source1 = env.addSource(new MyNonWatermarkingSource(numElements));
	DataStream<Integer> source2 = env.addSource(new MyNonWatermarkingSource(numElements));

	source1
			.map(new IdentityMap())
			.connect(source2).map(new IdentityCoMap())
			.transform("Custom Operator", BasicTypeInfo.INT_TYPE_INFO, new DisabledTimestampCheckingOperator())
			.addSink(new DiscardingSink<Integer>());

	env.execute();
}
 

private static OperatorID getOperatorID() {

		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
		env.setParallelism(1);

		env
			.fromElements(1, 2, 3)
			.uid(UID).name(OPERATOR_NAME)
			.disableChaining()
			.addSink(new DiscardingSink<>());

		JobGraph graph = env.getStreamGraph().getJobGraph(new JobID());
		JobVertex vertex = StreamSupport.stream(graph.getVertices().spliterator(), false)
			.filter(node -> node.getName().contains(OPERATOR_NAME))
			.findFirst()
			.orElseThrow(() -> new IllegalStateException("Unable to find vertex"));

		return vertex.getOperatorIDs().get(0);
	}
 

public static void main(String[] args) throws Exception {
	final ParameterTool pt = ParameterTool.fromArgs(args);
	final String checkpointDir = pt.getRequired("checkpoint.dir");

	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setStateBackend(new FsStateBackend(checkpointDir));
	env.setRestartStrategy(RestartStrategies.noRestart());
	env.enableCheckpointing(1000L);
	env.getConfig().disableGenericTypes();

	env.addSource(new MySource()).uid("my-source")
			.keyBy(anInt -> 0)
			.map(new MyStatefulFunction()).uid("my-map")
			.addSink(new DiscardingSink<>()).uid("my-sink");
	env.execute();
}
 

/**
 * Test for the temporary fix to FLINK-13063.
 */
@Test
public void testAsyncOperatorIsNeverChained() {
	StreamExecutionEnvironment chainEnv = StreamExecutionEnvironment.getExecutionEnvironment();

	DataStream<Integer> input = chainEnv.fromElements(1);
	input = AsyncDataStream.orderedWait(
		input,
		new LazyAsyncFunction(),
		TIMEOUT,
		TimeUnit.MILLISECONDS,
		6).map((x) -> x);
	AsyncDataStream.unorderedWait(
		input,
		new MyAsyncFunction(),
		TIMEOUT,
		TimeUnit.MILLISECONDS,
		3).map((x) -> x).addSink(new DiscardingSink<>());

	final JobGraph jobGraph = chainEnv.getStreamGraph().getJobGraph();

	Assert.assertEquals(3, jobGraph.getVerticesSortedTopologicallyFromSources().size());
}
 

/**
 * Tests that the max parallelism is properly set for connected
 * streams.
 */
@Test
public void testMaxParallelismWithConnectedKeyedStream() {
	int maxParallelism = 42;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	DataStream<Integer> input1 = env.fromElements(1, 2, 3, 4).setMaxParallelism(128);
	DataStream<Integer> input2 = env.fromElements(1, 2, 3, 4).setMaxParallelism(129);

	env.getConfig().setMaxParallelism(maxParallelism);

	DataStream<Integer> keyedResult = input1
			.connect(input2)
			.keyBy(value -> value, value -> value)
			.map(new NoOpIntCoMap());

	keyedResult.addSink(new DiscardingSink<>());

	StreamGraph graph = env.getStreamGraph();

	StreamNode keyedResultNode = graph.getStreamNode(keyedResult.getId());

	StreamPartitioner<?> streamPartitioner1 = keyedResultNode.getInEdges().get(0).getPartitioner();
	StreamPartitioner<?> streamPartitioner2 = keyedResultNode.getInEdges().get(1).getPartitioner();
}
 

/**
 * Tests that there are no collisions with two identical sources.
 *
 * <pre>
 * [ (src0) ] --\
 *               +--> [ (sink) ]
 * [ (src1) ] --/
 * </pre>
 */
@Test
public void testNodeHashIdenticalSources() throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.createLocalEnvironment();
	env.setParallelism(4);
	env.disableOperatorChaining();

	DataStream<String> src0 = env.addSource(new NoOpSourceFunction());
	DataStream<String> src1 = env.addSource(new NoOpSourceFunction());

	src0.union(src1).addSink(new DiscardingSink<>());

	JobGraph jobGraph = env.getStreamGraph().getJobGraph();

	List<JobVertex> vertices = jobGraph.getVerticesSortedTopologicallyFromSources();
	assertTrue(vertices.get(0).isInputVertex());
	assertTrue(vertices.get(1).isInputVertex());

	assertNotNull(vertices.get(0).getID());
	assertNotNull(vertices.get(1).getID());

	assertNotEquals(vertices.get(0).getID(), vertices.get(1).getID());
}
 

/**
 * Test whether an {@link OutputTypeConfigurable} implementation gets called with the correct
 * output type. In this test case the output type must be BasicTypeInfo.INT_TYPE_INFO.
 */
@Test
public void testOutputTypeConfigurationWithOneInputTransformation() throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	DataStream<Integer> source = env.fromElements(1, 10);

	OutputTypeConfigurableOperationWithOneInput outputTypeConfigurableOperation = new OutputTypeConfigurableOperationWithOneInput();

	DataStream<Integer> result = source.transform(
		"Single input and output type configurable operation",
		BasicTypeInfo.INT_TYPE_INFO,
		outputTypeConfigurableOperation);

	result.addSink(new DiscardingSink<>());

	env.getStreamGraph();

	assertEquals(BasicTypeInfo.INT_TYPE_INFO, outputTypeConfigurableOperation.getTypeInformation());
}
 

/**
 * Ensure that the consumer is properly failing if "auto.offset.reset" is set to "none".
 */
public void runFailOnAutoOffsetResetNone() throws Exception {
	final String topic = "auto-offset-reset-none-test";
	final int parallelism = 1;

	kafkaServer.createTestTopic(topic, parallelism, 1);

	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(parallelism);
	env.setRestartStrategy(RestartStrategies.noRestart()); // fail immediately
	env.getConfig().disableSysoutLogging();

	// ----------- add consumer ----------

	Properties customProps = new Properties();
	customProps.putAll(standardProps);
	customProps.putAll(secureProps);
	customProps.setProperty("auto.offset.reset", "none"); // test that "none" leads to an exception
	FlinkKafkaConsumerBase<String> source = kafkaServer.getConsumer(topic, new SimpleStringSchema(), customProps);

	DataStreamSource<String> consuming = env.addSource(source);
	consuming.addSink(new DiscardingSink<String>());

	try {
		env.execute("Test auto offset reset none");
	} catch (Throwable e) {
		// check if correct exception has been thrown
		if (!e.getCause().getCause().getMessage().contains("Unable to find previous offset")  // kafka 0.8
			&& !e.getCause().getCause().getMessage().contains("Undefined offset with no reset policy for partition") // kafka 0.9
				) {
			throw e;
		}
	}

	kafkaServer.deleteTestTopic(topic);
}
 

private static JobGraph createJobGraphWithOperatorState(
		int parallelism, int maxParallelism, OperatorCheckpointMethod checkpointMethod) {

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(parallelism);
	env.getConfig().setMaxParallelism(maxParallelism);
	env.enableCheckpointing(Long.MAX_VALUE);
	env.setRestartStrategy(RestartStrategies.noRestart());

	StateSourceBase.workStartedLatch = new CountDownLatch(parallelism);

	SourceFunction<Integer> src;

	switch (checkpointMethod) {
		case CHECKPOINTED_FUNCTION:
			src = new PartitionedStateSource(false);
			break;
		case CHECKPOINTED_FUNCTION_BROADCAST:
			src = new PartitionedStateSource(true);
			break;
		case LIST_CHECKPOINTED:
			src = new PartitionedStateSourceListCheckpointed();
			break;
		case NON_PARTITIONED:
			src = new NonPartitionedStateSource();
			break;
		default:
			throw new IllegalArgumentException();
	}

	DataStream<Integer> input = env.addSource(src);

	input.addSink(new DiscardingSink<Integer>());

	return env.getStreamGraph().getJobGraph();
}
 

/**
 * Tests that the max parallelism is automatically set to the parallelism if it has not been
 * specified.
 */
@Test
public void testAutoMaxParallelism() {
	int globalParallelism = 42;
	int mapParallelism = 17;
	int maxParallelism = 21;
	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(globalParallelism);

	DataStream<Integer> source = env.fromElements(1, 2, 3);

	DataStream<Integer> keyedResult1 = source.keyBy(value -> value).map(new NoOpIntMap());

	DataStream<Integer> keyedResult2 = keyedResult1.keyBy(value -> value).map(new NoOpIntMap()).setParallelism(mapParallelism);

	DataStream<Integer> keyedResult3 = keyedResult2.keyBy(value -> value).map(new NoOpIntMap()).setMaxParallelism(maxParallelism);

	DataStream<Integer> keyedResult4 = keyedResult3.keyBy(value -> value).map(new NoOpIntMap()).setMaxParallelism(maxParallelism).setParallelism(mapParallelism);

	keyedResult4.addSink(new DiscardingSink<>());

	StreamGraph graph = env.getStreamGraph();

	StreamNode keyedResult3Node = graph.getStreamNode(keyedResult3.getId());
	StreamNode keyedResult4Node = graph.getStreamNode(keyedResult4.getId());

	assertEquals(maxParallelism, keyedResult3Node.getMaxParallelism());
	assertEquals(maxParallelism, keyedResult4Node.getMaxParallelism());
}
 

public static JobGraph stoppableJob(final StopJobSignal stopJobSignal) {
	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	env.addSource(new InfiniteSourceFunction(stopJobSignal))
		.setParallelism(2)
		.shuffle()
		.addSink(new DiscardingSink<>())
		.setParallelism(2);

	return env.getStreamGraph().getJobGraph();
}
 

@Test
public void test() throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(1);

	env.addSource(new TestSource()).map(new TestMap()).addSink(new DiscardingSink<Integer>());
	env.execute();

	assertNotEquals(srcContext, mapContext);

}
 

public static void main(String[] args) throws Exception {
	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	final DataStreamSource<Integer> source = env.fromElements(1, 2, 3, 4);
	final SingleOutputStreamOperator<Integer> mapper = source.map(element -> 2 * element);
	mapper.addSink(new DiscardingSink<>());

	ParameterTool parameterTool = ParameterTool.fromArgs(args);
	env.execute(TestJob.class.getCanonicalName() + "-" + parameterTool.getRequired("arg"));
}
 

@Test
public void testDistributeFileViaDFS() throws Exception {

	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(1);

	env.registerCachedFile(testFile.toString(), "test_data", false);
	env.registerCachedFile(testDir.toString(), "test_dir", false);

	env.fromElements(1)
		.map(new TestMapFunction())
		.addSink(new DiscardingSink<>());

	env.execute("Distributed Cache Via Blob Test Program");
}
 

@Test
public void testSources() {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	SourceFunction<Integer> srcFun = new SourceFunction<Integer>() {
		private static final long serialVersionUID = 1L;

		@Override
		public void run(SourceContext<Integer> ctx) throws Exception {
		}

		@Override
		public void cancel() {
		}
	};
	DataStreamSource<Integer> src1 = env.addSource(srcFun);
	src1.addSink(new DiscardingSink<Integer>());
	assertEquals(srcFun, getFunctionFromDataSource(src1));

	List<Long> list = Arrays.asList(0L, 1L, 2L);

	DataStreamSource<Long> src2 = env.generateSequence(0, 2);
	assertTrue(getFunctionFromDataSource(src2) instanceof StatefulSequenceSource);

	DataStreamSource<Long> src3 = env.fromElements(0L, 1L, 2L);
	assertTrue(getFunctionFromDataSource(src3) instanceof FromElementsFunction);

	DataStreamSource<Long> src4 = env.fromCollection(list);
	assertTrue(getFunctionFromDataSource(src4) instanceof FromElementsFunction);
}
 

@SuppressWarnings("unchecked")
private static <T> SourceFunction<T> getFunctionFromDataSource(DataStreamSource<T> dataStreamSource) {
	dataStreamSource.addSink(new DiscardingSink<T>());
	AbstractUdfStreamOperator<?, ?> operator =
			(AbstractUdfStreamOperator<?, ?>) getOperatorFromDataStream(dataStreamSource);
	return (SourceFunction<T>) operator.getUserFunction();
}
 

/**
 * Tests that a manual hash for an intermediate chain node is accepted.
 */
@Test
public void testManualHashAssignmentForIntermediateNodeInChain() throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.createLocalEnvironment();
	env.setParallelism(4);

	env.addSource(new NoOpSourceFunction())
			// Intermediate chained node
			.map(new NoOpMapFunction()).uid("map")
			.addSink(new DiscardingSink<>());

	env.getStreamGraph().getJobGraph();
}
 

/**
 * Tests that the global and operator-wide max parallelism setting is respected.
 */
@Test
public void testMaxParallelismForwarding() {
	int globalMaxParallelism = 42;
	int keyedResult2MaxParallelism = 17;

	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
	env.getConfig().setMaxParallelism(globalMaxParallelism);

	DataStream<Integer> source = env.fromElements(1, 2, 3);

	DataStream<Integer> keyedResult1 = source.keyBy(value -> value).map(new NoOpIntMap());

	DataStream<Integer> keyedResult2 = keyedResult1
			.keyBy(value -> value)
			.map(new NoOpIntMap())
				.setMaxParallelism(keyedResult2MaxParallelism);

	keyedResult2.addSink(new DiscardingSink<>());

	StreamGraph graph = env.getStreamGraph();

	StreamNode keyedResult1Node = graph.getStreamNode(keyedResult1.getId());
	StreamNode keyedResult2Node = graph.getStreamNode(keyedResult2.getId());

	assertEquals(globalMaxParallelism, keyedResult1Node.getMaxParallelism());
	assertEquals(keyedResult2MaxParallelism, keyedResult2Node.getMaxParallelism());
}
 

public static JobGraph stoppableJob(final StopJobSignal stopJobSignal) {
	final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	env.addSource(new InfiniteSourceFunction(stopJobSignal))
		.setParallelism(2)
		.shuffle()
		.addSink(new DiscardingSink<>())
		.setParallelism(2);

	return env.getStreamGraph().getJobGraph();
}